Salt and polymorphic forms of (3r,4s)-l-((4-amino-5h-pyrrolo[3,2,-d]pyrimidin-7-yl)methyl)-4(methylthiomethyl)pyrodin-3-ol(mtdia)

ABSTRACT

The invention relates to salt forms of (3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methyl-thiomethyl)pyrrolidin-3-ol, as well as polymorphic forms of the salts. The invention further relates to processes for preparing the salt forms and to the use of the salt forms in the treatment of diseases and disorders where it is desirable to inhibit 5′-methylthioadenosine phosphorylase (MTAP).

TECHNICAL FIELD

This invention relates to salt forms of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,compound (I) (MTDIA), as well as polymorphic forms of the salts. Theinvention further relates to processes for preparing the salt forms andto the use of the salt forms in the treatment, of diseases and disorderswhere it is desirable to inhibit 5′-methylthioadenosine phosphorylase(MTAP), such as cancer.

BACKGROUND

5′-Methylthioadenosine phosphorylase (MTAP) functions in the polyaminebiosynthesis pathway, in purine salvage in mammals. It catalyses thereversible phosphorolysis of 5′-methylthioadenosine (MTA) to adenine and5-methylthio-α-D-ribose-1-phosphate (MTR-1P). The adenine formed issubsequently recycled and converted into nucleotides. Essentially, theonly source of free adenine in the human cell is a result of the actionof these enzymes. The MTR-1P is subsequently converted into methionineby successive enzymatic actions.

MTA is a by-product of the reaction involving the transfer of anaminopropyl group from decarboxylated S-adenosyl methionine toputrescine during the formation of spermidine and spermine. Thereactions are catalyzed by spermidine synthase and spermine synthase.The synthases are very sensitive to product inhibition by accumulationof MTA. Therefore, inhibition of MTAP severely limits the polyaminebiosynthesis and the salvage pathway for adenine in the cells.

MTAP deficiency due to a genetic deletion has been reported with manymalignancies. The loss of MTAP enzyme function in these cells is knownto be due to homozygous deletions on chromosome 9 of the closely linkedMTAP and p16/MTS1 tumour suppressor gene. As absence of p16/MTS1 isprobably responsible for the tumour, the lack of MTAP activity is aconsequence of the genetic deletion and is not causative for the cancer.However, the absence of MTAP alters the purine metabolism in these cellsso that they are mainly dependent on the de novo pathway for theirsupply of purines. That makes these cells unusually sensitive toinhibitors like methotrexate and azaserine that block the de novopathway. Therefore, a combination therapy of methotrexate or azaserinewith an MTAP inhibitor will have unusually effective anti-tumourproperties.

WO 2004/018496 describes compounds, including MTDIA, which areinhibitors of nucleoside processing enzymes. US 2010/0222370 describesthat MTDIA is useful in the treatment of prostate and head and neckcancers.

It is an object of the invention to provide salt forms of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,or to at least provide the public with a useful alternative.

STATEMENTS OF INVENTION

In a first aspect the invention provides a salt form of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,selected from the group consisting of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate and(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate.

In another aspect the invention provides a crystalline salt form of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,selected from the group consisting of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate and(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate.

In another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, a compound of formula (Ia):

In another aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.

In still another aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form D characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.38, 7.10, 8.93, 10.87, 13.06,14.31, 15.81, 17.59, 17.92, 19.97, 21.53, 22.76, 26.00, 27.06, 27.79,28.95 and 29.97 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 19.1, 14.4, 11.49,9.44, 7.87, 7.18, 6.50, 5.85, 5.74, 5.16, 4.79, 4.53, 3.977, 3.823,3.725, 3.579 and 3.459 Å.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form D is further characterised by one or more additionalX-ray power diffraction peaks at the following 2 theta angles: about14.57, 15.32, 16.50, 19.07, 20.17, 20.77, 21.78, 22.22, 23.12, 24.84,25.75, 26.31, 28.14, 28.57, 29.35, 30.50, 30.91, 31.35, 32.64, 32.09,34.17, 33.33 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 7.05, 6.71, 6.23, 5.40,5.11, 4.96, 4.73, 4.64, 4.46, 4.159, 4.014, 3.931, 3.679, 3.625, 3.531,3.401, 3.357, 3.311, 3.183, 3.236, 3.045, 3.119 Å.

In a further aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form D having an X-ray power diffraction pattern substantiallyas shown in FIG. 3( a).

In still another aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form E characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.26, 7.01, 8.69, 10.58, 15.95,17.26, 17.57, 21.27, 21.60, 22.75, 25.64, 26.88, 28.86, 29.99 and 30.75degrees 2 theta±0.05 degrees 2 theta, which correspond, respectively, tothe following d-spacings: about 19.5, 14.6, 11.81, 9.70, 6.45, 5.96,5.86, 4.85, 4.77, 4.54, 4.031, 3.849, 3.589, 3.457 and 3.374 Å.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form E is further characterised by one or more additionalX-ray power diffraction peaks at the following 2 theta angles: about8.91, 12.56, 16.76, 17.84, 19.36, 20.14, 20.86, 22.09, 22.53, 23.03,24.14, 25.95, 26.16, 26.63, 27.72, 29.35, 30.22, 31.11, 31.57, 32.38,33.04, 33.38, 33.93 degrees 2 theta±0.05 degrees 2 theta, whichcorrespond, respectively, to the following d-spacings: about 11.52,8.18, 6.14, 5.77, 5.32, 5.12, 4.94, 4.67, 4.58, 4.48, 4.278, 3.984,3.952, 3.884, 3.734, 3.531, 3.431, 3.336, 3.288, 3.208, 3.146, 3.115,3.066 Å.

In a further aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form E having an X-ray power diffraction pattern substantiallyas shown in FIG. 4( a).

In still another aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form F characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.25, 7.00, 8.73, 10.67, 15.82,16.04, 17.52, 17.75, 20.13, 20.77, 21.36, 21.72, 22.79, 25.70, 26.10,28.55, 29.56, 30.52, 31.43 and 32.42 degrees 2 theta±0.05 degrees 2theta, which correspond, respectively, to the following d-spacings:about 19.5, 14.7, 11.76, 9.62, 6.50, 6.41, 5.87, 5.80, 5.12, 4.97, 4.83,4.75, 4.53, 4.022, 3.962, 3.627, 3.506, 3.398, 3.303 and 3.204 Å.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form F is further characterised by one or more additionalX-ray power diffraction peaks at the following 2 theta angles: about8.92, 12.69, 14.19, 15.14, 16.68, 19.21, 22.09, 23.60, 24.35, 24.80,26.81, 27.00, 27.81, 29.01, 29.88, 32.12, 32.95, 33.68, 34.08, 35.08,35.84, 36.58, 37.32, 39.18, 40.37, 40.79, 41.84, 42.56, 43.62, 44.51,46.14, 46.52, 47.00, 48.24, 49.02, 49.54 degrees 2 theta±0.05 degrees 2theta, which correspond, respectively, to the following d-spacings:about 11.50, 8.09, 7.25, 6.79, 6.17, 5.36, 4.67, 4.374, 4.241, 4.165,3.859, 3.832, 3.722, 3.571, 3.469, 3.233, 3.154, 3.088, 3.052, 2.968,2.907, 2.850, 2.795, 2.668, 2.592, 2.567, 2.505, 2.464, 2.408, 2.362,2.283, 2.265, 2.243, 2.189, 2.156, 2.135 Å.

In a further aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form F having an X-ray power diffraction pattern substantiallyas shown in FIG. 5( a).

In still another aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate characterised by X-ray power diffraction peaks at the following2 theta angles: about 6.22, 12.35, 13.54, 18.23, 20.47, 21.94, 24.22 and29.44 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 16.5, 8.32, 7.59, 5.65,5.03, 4.70, 4.263 and 3.520 Å.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 14.94, 15.72,19.11, 22.54, 30.07, 31.11, 32.06, 32.71, 33.90 degrees 2 theta±0.05degrees 2 theta, which correspond, respectively, to the followingd-spacings: about 6.88, 6.54, 5.39, 4.58, 3.448, 3.336, 3.239, 3.177,3.068 Å.

In a further aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate having an X-ray power diffraction pattern substantially as shownin FIG. 1( a).

In still another aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate characterised by X-ray power diffraction peaks at the following2 theta angles: about 8.11, 16.30, 20.68, 24.85, 25.70, 26.03, 28.00,32.23 and 33.02 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 12.65, 6.31, 4.98,4.157, 4.022, 3.972, 3.698, 3.223 and 3.147 Å.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 10.34, 13.66,17.54, 17.95, 18.83, 21.32, 21.71, 23.17, 24.63, 27.13, 27.57, 28.51,28.77, 30.33, 31.05, 31.24, 33.45, 34.24, 34.52, 35.57, 35.99, 36.66,36.93, 38.15, 38.91, 39.94, 40.47, 41.45, 42.17, 42.75, 44.36, 45.15,46.27, 46.50, 47.36, 48.49, 49.20, 50.12 degrees 2 theta±0.05 degrees 2theta, which correspond, respectively, to the following d-spacings:about 9.93, 7.52, 5.87, 5.74, 5.47, 4.84, 4.75, 4.45, 4.194, 3.814,3.754, 3.632, 3.600, 3.420, 3.342, 3.322, 3.108, 3.039, 3.014, 2.929,2.896, 2.845, 2.825, 2.737, 2.686, 2.619, 2.586, 2.528, 2.486, 2.454,2.369, 2.330, 2.277, 2.266, 2.227, 2.178, 2.149, 2.112 Å.

In a further aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate having an X-ray power diffraction pattern substantially as shownin FIG. 6( a).

In still another aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate characterised by X-ray power diffraction peaks at the following2 theta angles: about 5.75, 10.33, 13.14, 15.41, 15.90, 17.61, 18.32,21.43, 24.30, 26.15, 26.76, 27.67, 30.28, 30.97, 31.52 and 32.27 degrees2 theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 17.8, 9.94, 7.82, 6.67, 6.47, 5.84, 5.62,4.81, 4.25, 3.954, 3.866, 3.741, 3.425, 3.35, 3.293 and 3.219 Å.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 19.14, 20.28,20.87, 22.26, 24.64, 29.37, 33.24 degrees 2 theta±0.05 degrees 2 theta,which correspond, respectively, to the following d-spacings: about 5.38,5.08, 4.94, 4.63, 4.192, 3.529, 3.127 Å.

In a further aspect the invention provides crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate having an X-ray power diffraction pattern substantially as shownin FIG. 2( a).

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate which exhibits an endotherm at a range of about 165° C. toabout 185° C. as measured by differential scanning calorimetry.

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form D, having a differential scanning calorimetrythermogram substantially as shown in FIG. 3( c).

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form E, having a differential scanning calorimetrythermogram substantially as shown in FIG. 4( c).

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form F, having a differential scanning calorimetrythermogram substantially as shown in FIG. 5( c).

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate which exhibits an endotherm at about 137.04° C. as measured bydifferential scanning calorimetry.

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate, having a differential scanning calorimetry thermogramsubstantially as shown in FIG. 1( b).

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate which exhibits an endotherm at about 179.54° C. as measured bydifferential scanning calorimetry.

In still another aspect the invention provides(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate, having a differential scanning calorimetry thermogramsubstantially as shown in FIG. 6( c).

Preferably the(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate is crystalline.

In a further aspect the invention provides a pharmaceutical compositioncomprising(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, preferably(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, more preferably crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, and at least one pharmaceutically acceptable excipient.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is characterised by X-ray power diffraction peaks at thefollowing 2 theta angles: about 5.38, 7.10, 8.93, 10.87, 13.06, 14.31,15.81, 17.59, 17.92, 19.97, 21.53, 22.76, 26.00, 27.06, 27.79, 28.95 and29.97 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 19.1, 14.4, 11.49,9.44, 7.87, 7.18, 6.50, 5.85, 5.74, 5.16, 4.79, 4.53, 3.977, 3.823,3.725, 3.579 and 3.459 Å. More preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 14.57, 15.32,16.50, 19.07, 20.17, 20.77, 21.78, 22.22, 23.12, 24.84, 25.75, 26.31,28.14, 28.57, 29.35, 30.50, 30.91, 31.35, 32.64, 32.09, 34.17, 33.33degrees 2 theta±0.05 degrees 2 theta, which correspond, respectively, tothe following d-spacings: about 7.05, 6.71, 6.23, 5.40, 5.11, 4.96,4.73, 4.64, 4.46, 4.159, 4.014, 3.931, 3.679, 3.625, 3.531, 3.401,3.357, 3.311, 3.183, 3.236, 3.045, 3.119 Å.

Alternatively preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is characterised by X-ray power diffraction peaks at thefollowing 2 theta angles about 5.26, 7.01, 8.69, 10.58, 15.95, 17.26,17.57, 21.27, 21.60, 22.75, 25.64, 26.88, 28.86, 29.99 and 30.75 degrees2 theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 19.5, 14.6, 11.81, 9.70, 6.45, 5.96, 5.86,4.85, 4.77, 4.54, 4.031, 3.849, 3.589, 3.457 and 3.374 Å. Morepreferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 8.91, 12.56,16.76, 17.84, 19.36, 20.14, 20.86, 22.09, 22.53, 23.03, 24.14, 25.95,26.16, 26.63, 27.72, 29.35, 30.22, 31.11, 31.57, 32.38, 33.04, 33.38,33.93 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 11.52, 8.18, 6.14,5.77, 5.32, 5.12, 4.94, 4.67, 4.58, 4.48, 4.278, 3.984, 3.952, 3.884,3.734, 3.531, 3.431, 3.336, 3.288, 3.208, 3.146, 3.115, 3.066 Å.

Alternatively preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is characterised by X-ray power diffraction peaks at thefollowing 2 theta angles: about 5.25, 7.00, 8.73, 10.67, 15.82, 16.04,17.52, 17.75, 20.13, 20.77, 21.36, 21.72, 22.79, 25.70, 26.10, 28.55,29.56, 30.52, 31.43 and 32.42 degrees 2 theta±0.05 degrees 2 theta,which correspond, respectively, to the following d-spacings: about 19.5,14.7, 11.76, 9.62, 6.50, 6.41, 5.87, 5.80, 5.12, 4.97, 4.83, 4.75, 4.53,4.022, 3.962, 3.627, 3.506, 3.398, 3.303 and 3.204 Å. More preferablythe crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 8.92, 12.69,14.19, 15.14, 16.68, 19.21, 22.09, 23.60, 24.35, 24.80, 26.81, 27.00,27.81, 29.01, 29.88, 32.12, 32.95, 33.68, 34.08, 35.08, 35.84, 36.58,37.32, 39.18, 40.37, 40.79, 41.84, 42.56, 43.62, 44.51, 46.14, 46.52,47.00, 48.24, 49.02, 49.54 degrees 2 theta±0.05 degrees 2 theta, whichcorrespond, respectively, to the following d-spacings: about 11.50,8.09, 7.25, 6.79, 6.17, 5.36, 4.67, 4.374, 4.241, 4.165, 3.859, 3.832,3.722, 3.571, 3.469, 3.233, 3.154, 3.088, 3.052, 2.968, 2.907, 2.850,2.795, 2.668, 2.592, 2.567, 2.505, 2.464, 2.408, 2.362, 2.283, 2.265,2.243, 2.189, 2.156, 2.135 Å.

In a yet another aspect, the invention provides a method of treating adisease or disorder in which it is desirable to inhibit MTAP, comprisingadministering an effective amount of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, preferably(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, to a patient in need thereof.

In still another aspect the invention provides the use of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, preferably(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, as a medicament.

In still another aspect the invention provides the use of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, preferably(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, in the manufacture of a medicament.

In still another aspect the invention provides the use of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, preferably(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, in the manufacture of a medicament for treating a disease ordisorder in which it is desirable to inhibit MTAP.

In still another aspect the invention provides a pharmaceuticalcomposition comprising(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, preferably(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, for use in treating a disease or disorder in which it isdesirable to inhibit MTAP.

Preferably the(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.

Preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is characterised by X-ray power diffraction peaks at thefollowing 2 theta angles: about 5.38, 7.10, 8.93, 10.87, 13.06, 14.31,15.81, 17.59, 17.92, 19.97, 21.53, 22.76, 26.00, 27.06, 27.79, 28.95 and29.97 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 19.1, 14.4, 11.49,9.44, 7.87, 7.18, 6.50, 5.85, 5.74, 5.16, 4.79, 4.53, 3.977, 3.823,3.725, 3.579 and 3.459 Å. More preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 14.57, 15.32,16.50, 19.07, 20.17, 20.77, 21.78, 22.22, 23.12, 24.84, 25.75, 26.31,28.14, 28.57, 29.35, 30.50, 30.91, 31.35, 32.64, 32.09, 34.17, 33.33degrees 2 theta±0.05 degrees 2 theta, which correspond, respectively, tothe following d-spacings: about 7.05, 6.71, 6.23, 5.40, 5.11, 4.96,4.73, 4.64, 4.46, 4.159, 4.014, 3.931, 3.679, 3.625, 3.531, 3.401,3.357, 3.311, 3.183, 3.236, 3.045, 3.119 Å.

Alternatively preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is characterised by X-ray power diffraction peaks at thefollowing 2 theta angles about 5.26, 7.01, 8.69, 10.58, 15.95, 17.26,17.57, 21.27, 21.60, 22.75, 25.64, 26.88, 28.86, 29.99 and 30.75 degrees2 theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 19.5, 14.6, 11.81, 9.70, 6.45, 5.96, 5.86,4.85, 4.77, 4.54, 4.031, 3.849, 3.589, 3.457 and 3.374 Å. Morepreferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 8.91, 12.56,16.76, 17.84, 19.36, 20.14, 20.86, 22.09, 22.53, 23.03, 24.14, 25.95,26.16, 26.63, 27.72, 29.35, 30.22, 31.11, 31.57, 32.38, 33.04, 33.38,33.93 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 11.52, 8.18, 6.14,5.77, 5.32, 5.12, 4.94, 4.67, 4.58, 4.48, 4.278, 3.984, 3.952, 3.884,3.734, 3.531, 3.431, 3.336, 3.288, 3.208, 3.146, 3.115, 3.066 Å.

Alternatively preferably the crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is characterised by X-ray power diffraction peaks at thefollowing 2 theta angles: about 5.25, 7.00, 8.73, 10.67, 15.82, 16.04,17.52, 17.75, 20.13, 20.77, 21.36, 21.72, 22.79, 25.70, 26.10, 28.55,29.56, 30.52, 31.43 and 32.42 degrees 2 theta±0.05 degrees 2 theta,which correspond, respectively, to the following d-spacings: about 19.5,14.7, 11.76, 9.62, 6.50, 6.41, 5.87, 5.80, 5.12, 4.97, 4.83, 4.75, 4.53,4.022, 3.962, 3.627, 3.506, 3.398, 3.303 and 3.204 Å. More preferablythe crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 8.92, 12.69,14.19, 15.14, 16.68, 19.21, 22.09, 23.60, 24.35, 24.80, 26.81, 27.00,27.81, 29.01, 29.88, 32.12, 32.95, 33.68, 34.08, 35.08, 35.84, 36.58,37.32, 39.18, 40.37, 40.79, 41.84, 42.56, 43.62, 44.51, 46.14, 46.52,47.00, 48.24, 49.02, 49.54 degrees 2 theta±0.05 degrees 2 theta, whichcorrespond, respectively, to the following d-spacings: about 11.50,8.09, 7.25, 6.79, 6.17, 5.36, 4.67, 4.374, 4.241, 4.165, 3.859, 3.832,3.722, 3.571, 3.469, 3.233, 3.154, 3.088, 3.052, 2.968, 2.907, 2.850,2.795, 2.668, 2.592, 2.567, 2.505, 2.464, 2.408, 2.362, 2.283, 2.265,2.243, 2.189, 2.156, 2.135 Å.

Preferably the disease or disorder is cancer, e.g. head and neckcancers, lung cancer, breast cancer, colon cancer, cervical cancer orprostate cancer.

The(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate may be administered with a second compound, e.g.methylthioadenosine. The compounds may be administered separately,sequentially or together.

In another aspect the invention provides a process for the preparationof crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, including the steps:

(a) preparing a solution of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate in water;(b) adding an alcohol, methyl ethyl ketone, tetrahydrofuran or acetoneto the solution, to form crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate; and(c) isolating the crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.

Preferably an alcohol is added in step (b), more preferably the alcoholis a C₁-C₆ alcohol, still more preferably the alcohol is methanol,ethanol, n-propanol or isopropanol, even more preferably the alcohol ismethanol or ethanol. It is further preferred that the ratio of ethanolto water in step (b) is at least about 50% ethanol, e.g. about 55:45ethanol:water, e.g. about 60:40 ethanol:water.

Alternatively, it is preferred that the ratio of ethanol to water instep (b) is less than about 50% ethanol, e.g. about 45:55 ethanol:water,e.g. about 40:60 ethanol:water.

In another aspect, the invention provides a process for preparing acompound of formula (V)

including the steps:(d) reacting a compound of formula (III) with methyl chloroformate toproduce a compound of formula (IV)

and(e) cyclisation of the compound of formula (IV) under basic conditionsto give the compound of formula (V);wherein ethyl acetate is employed as a solvent in step (d).

Preferably DBU is employed as a base in the cyclisation step (e). Morepreferably DBU and dichloromethane are employed as base and solvent,respectively, in the cyclisation step (e). It is further preferred thata reaction time of less than about 15 minutes, e.g. about 10 minutes, isemployed in step (e). It is also preferred that, after the reaction timeof less than about 15 minutes in step (e), methanol, followed byammonium acetate, are added to the reaction.

In still another aspect, the invention provides a process for preparinga compound of formula (XII)

including the steps:(f) contacting a compound of formula (IX) with methanesulfonyl chlorideand 2,6-lutidine followed by sodium thiomethoxide to give a compound offormula (X)

(g) deprotection of the compound of formula (X) followed by conversionto a compound of formula (XI)

and(h) conversion of the compound of formula (XI) to the compound offormula (XII);wherein acetone is employed as a solvent in step (f).

Preferably the deprotection of the compound of formula (X) in step (g)is carried out by contacting the compound of formula (X) withtrifluoroacetic acid. It is further preferred that the conversion tocompound (XI) in step (g) is carried out by contacting the deprotectedcompound of formula (X) with a resin such as a food grade strong baseanionic exchange resin. It is also preferred that the conversion of thecompound of formula (XI) to the compound (XII) in step (h) is carriedout by contacting the compound of formula (XI) with a resin such as afood grade strong base anionic exchange resin.

In still another aspect, the invention provides a process for preparing(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, including the steps:

(a) contacting a compound of formula (XII) with 9-deazaadenine andformaldehyde in water/ethanol solvent to produce(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol

(b) contacting the(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olproduced in step (a) with:(i) a solution of phosphoric acid in water, to produce a solutioncontaining(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate;(ii) seed crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate; and optionally(iii) ethanol;to produce crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate;(c) isolating crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.

Preferably the ratio of water to ethanol in step (a) is about 4:1. It isfurther preferred that the reaction mixture in step (a) is stirred atambient temperature for about 2 days.

Preferably the ethanol is added stepwise, in portions, in step (b). Itis further preferred that the ethanol is added over a time period ofabout two hours.

DETAILED DESCRIPTION

Salt forms of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,particularly as exemplified, e.g.(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, compound (Ia):

or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, are useful as a pharmaceuticals, for example for the treatmentof diseases or disorders where it is desirable to inhibit MTAP, such ascancers, e.g. head and neck cancers, lung cancer, breast cancer, coloncancer, cervical cancer or prostate cancer.

For example, FIG. 8 shows a study of the effect of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate on larger tumours (150 mm³). The study uses MDA-MB-468 tumoursgrown orthotopically for 35 days in a mouse xenograft model. Treatmentcauses the 150 mm³ tumours to shrink by half within days and suppressesgrowth for the subsequent 30 days. Doses of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate from 24 to 30.5 mg/kg are equally effective at stopping cancergrowth. Upon drug release, tumour size increases slowly relative tountreated tumours. Control tumours grow from 150 to 400 mm³ over 35days. At day 71, the large tumours are treated with 30 mg/kg i.p.(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate. The tumours undergo rapid decrease in size as a consequenceof tumour lysis with most of the tumours resolved over a two-weekperiod.

Those skilled in the art will appreciate that salt forms of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,such as(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate or(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, can exist as solvates. For example, crystalline forms of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate and(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate can contain waters of crystallisation.

Advantageously, the phosphate salt of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olof the present invention provides improved stability and solubility. Thephosphate salt of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olcan be crystallised directly from the reaction mixture providing theproduct in high purity. This is not achievable with the free base formor the hydrochloride salt form. The phosphate salt of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olis suitable for large scale production, particularly because it can bepurified by recrystallisation, whereas previously the only method topurify(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olwas by chromatography.

The present invention provides:1. A salt form of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,selected from the group consisting of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate and(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate.2. A salt form of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olas described in the above paragraph 1, which is crystalline.3. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, a compound of formula (Ia):

4. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form D characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.38, 7.10, 8.93, 10.87, 13.06,14.31, 15.81, 17.59, 17.92, 19.97, 21.53, 22.76, 26.00, 27.06, 27.79,28.95 and 29.97 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 19.1, 14.4, 11.49,9.44, 7.87, 7.18, 6.50, 5.85, 5.74, 5.16, 4.79, 4.53, 3.977, 3.823,3.725, 3.579 and 3.459 Å.5. A salt form as described in the above paragraph 4 which is furthercharacterised by one or more additional X-ray power diffraction peaks atthe following 2 theta angles: about 14.57, 15.32, 16.50, 19.07, 20.17,20.77, 21.78, 22.22, 23.12, 24.84, 25.75, 26.31, 28.14, 28.57, 29.35,30.50, 30.91, 31.35, 32.64, 32.09, 34.17, 33.33 degrees 2 theta±0.05degrees 2 theta, which correspond, respectively, to the followingd-spacings: about 7.05, 6.71, 6.23, 5.40, 5.11, 4.96, 4.73, 4.64, 4.46,4.159, 4.014, 3.931, 3.679, 3.625, 3.531, 3.401, 3.357, 3.311, 3.183,3.236, 3.045, 3.119 Å.6. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form D having an X-ray power diffraction pattern substantiallyas shown in FIG. 3( a).7. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form E characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.26, 7.01, 8.69, 10.58, 15.95,17.26, 17.57, 21.27, 21.60, 22.75, 25.64, 26.88, 28.86, 29.99 and 30.75degrees 2 theta±0.05 degrees 2 theta, which correspond, respectively, tothe following d-spacings: about 19.5, 14.6, 11.81, 9.70, 6.45, 5.96,5.86, 4.85, 4.77, 4.54, 4.031, 3.849, 3.589, 3.457 and 3.374 Å.8. A salt form as described in the above paragraph 7 which is furthercharacterised by one or more additional X-ray power diffraction peaks atthe following 2 theta angles: about 8.91, 12.56, 16.76, 17.84, 19.36,20.14, 20.86, 22.09, 22.53, 23.03, 24.14, 25.95, 26.16, 26.63, 27.72,29.35, 30.22, 31.11, 31.57, 32.38, 33.04, 33.38, 33.93 degrees 2theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 11.52, 8.18, 6.14, 5.77, 5.32, 5.12, 4.94,4.67, 4.58, 4.48, 4.278, 3.984, 3.952, 3.884, 3.734, 3.531, 3.431,3.336, 3.288, 3.208, 3.146, 3.115, 3.066 Å.9. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form E having an X-ray power diffraction pattern substantiallyas shown in FIG. 4( a).10. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form F characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.25, 7.00, 8.73, 10.67, 15.82,16.04, 17.52, 17.75, 20.13, 20.77, 21.36, 21.72, 22.79, 25.70, 26.10,28.55, 29.56, 30.52, 31.43 and 32.42 degrees 2 theta±0.05 degrees 2theta, which correspond, respectively, to the following d-spacings:about 19.5, 14.7, 11.76, 9.62, 6.50, 6.41, 5.87, 5.80, 5.12, 4.97, 4.83,4.75, 4.53, 4.022, 3.962, 3.627, 3.506, 3.398, 3.303 and 3.204 Å.11. A salt form as described in the above paragraph 10 which is furthercharacterised by one or more additional X-ray power diffraction peaks atthe following 2 theta angles: about 8.92, 12.69, 14.19, 15.14, 16.68,19.21, 22.09, 23.60, 24.35, 24.80, 26.81, 27.00, 27.81, 29.01, 29.88,32.12, 32.95, 33.68, 34.08, 35.08, 35.84, 36.58, 37.32, 39.18, 40.37,40.79, 41.84, 42.56, 43.62, 44.51, 46.14, 46.52, 47.00, 48.24, 49.02,49.54 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 11.50, 8.09, 7.25,6.79, 6.17, 5.36, 4.67, 4.374, 4.241, 4.165, 3.859, 3.832, 3.722, 3.571,3.469, 3.233, 3.154, 3.088, 3.052, 2.968, 2.907, 2.850, 2.795, 2.668,2.592, 2.567, 2.505, 2.464, 2.408, 2.362, 2.283, 2.265, 2.243, 2.189,2.156, 2.135 Å.12. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form F having an X-ray power diffraction pattern substantiallyas shown in FIG. 5( a).13. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate characterised by X-ray power diffraction peaks at the following2 theta angles: about 6.22, 12.35, 13.54, 18.23, 20.47, 21.94, 24.22 and29.44 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 16.5, 8.32, 7.59, 5.65,5.03, 4.70, 4.263 and 3.520 Å.14. A salt form as described in the above paragraph 13 which is furthercharacterised by one or more additional X-ray power diffraction peaks atthe following 2 theta angles: about 14.94, 15.72, 19.11, 22.54, 30.07,31.11, 32.06, 32.71, 33.90 degrees 2 theta±0.05 degrees 2 theta, whichcorrespond, respectively, to the following d-spacings: about 6.88, 6.54,5.39, 4.58, 3.448, 3.336, 3.239, 3.177, 3.068 Å.15. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline.(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate having an X-ray power diffraction pattern substantially as shownin FIG. 1( a).16. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate characterised by X-ray power diffraction peaks at the following2 theta angles: about 8.11, 16.30, 20.68, 24.85, 25.70, 26.03, 28.00,32.23 and 33.02 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 12.65, 6.31, 4.98,4.157, 4.022, 3.972, 3.698, 3.223 and 3.147 Å.17. A salt form as described in the above paragraph 16 which is furthercharacterised by one or more additional X-ray power diffraction peaks atthe following 2 theta angles: about 10.34, 13.66, 17.54, 17.95, 18.83,21.32, 21.71, 23.17, 24.63, 27.13, 27.57, 28.51, 28.77, 30.33, 31.05,31.24, 33.45, 34.24, 34.52, 35.57, 35.99, 36.66, 36.93, 38.15, 38.91,39.94, 40.47, 41.45, 42.17, 42.75, 44.36, 45.15, 46.27, 46.50, 47.36,48.49, 49.20, 50.12 degrees 2 theta±0.05 degrees 2 theta, whichcorrespond, respectively, to the following d-spacings: about 9.93, 7.52,5.87, 5.74, 5.47, 4.84, 4.75, 4.45, 4.194, 3.814, 3.754, 3.632, 3.600,3.420, 3.342, 3.322, 3.108, 3.039, 3.014, 2.929, 2.896, 2.845, 2.825,2.737, 2.686, 2.619, 2.586, 2.528, 2.486, 2.454, 2.369, 2.330, 2.277,2.266, 2.227, 2.178, 2.149, 2.112 Å.18. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate having an X-ray power diffraction pattern substantially as shownin FIG. 6( a).19. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate characterised by X-ray power diffraction peaks at the following2 theta angles: about 5.75, 10.33, 13.14, 15.41, 15.90, 17.61, 18.32,21.43, 24.30, 26.15, 26.76, 27.67, 30.28, 30.97, 31.52 and 32.27 degrees2 theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 17.8, 9.94, 7.82, 6.67, 6.47, 5.84, 5.62,4.81, 4.25, 3.954, 3.866, 3.741, 3.425, 3.35, 3.293 and 3.219 Å.20. A salt form as described in the above paragraph 19 which is furthercharacterised by one or more additional X-ray power diffraction peaks atthe following 2 theta angles: about 19.14, 20.28, 20.87, 22.26, 24.64,29.37, 33.24 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 5.38, 5.08, 4.94, 4.63,4.192, 3.529, 3.127 Å.21. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate having an X-ray power diffraction pattern substantially as shownin FIG. 2( a).22. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate which exhibits an endotherm at a range of about 165° C. toabout 185° C. as measured by differential scanning calorimetry.23. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form D, having a differential scanning calorimetrythermogram substantially as shown in FIG. 3( c).24. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form E, having a differential scanning calorimetrythermogram substantially as shown in FIG. 4( c).25. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form F, having a differential scanning calorimetrythermogram substantially as shown in FIG. 5( c).26. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate which exhibits an endotherm at about 137.04° C. as measured bydifferential scanning calorimetry.27. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate, having a differential scanning calorimetry thermogramsubstantially as shown in FIG. 1( b).28. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate which exhibits an endotherm at about 179.54° C. as measured bydifferential scanning calorimetry.29. A salt form as described in the above paragraph 1 or the aboveparagraph 2 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate, having a differential scanning calorimetry thermogramsubstantially as shown in FIG. 6( c).30. A pharmaceutical composition comprising a salt form as described inany one of the above paragraphs 1 to 29 and at least onepharmaceutically acceptable excipient.31. A pharmaceutical composition as described in the above paragraph 30,wherein the salt form is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.32. A method of treating a disease or disorder in which it is desirableto inhibit MTAP, comprising administering an effective amount of a saltform as described in any one of the above paragraphs 1 to 29 to apatient in need thereof.33. A method as described in the above paragraph 32, wherein the saltform is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.34. A method as described in the above paragraph 32 or 33, wherein thedisease or disorder is cancer.35. A process for the preparation of crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, including the steps:(a) preparing a solution of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate in water;(b) adding an alcohol, methyl ethyl ketone, tetrahydrofuran or acetoneto the solution, to form crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate; and(c) isolating the crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.36. A process as described in the above paragraph 35 wherein ethanol isadded in step (b).37. A process for preparing a compound of formula (V)

-   -   including the steps:        (d) reacting a compound of formula (III) with methyl        chloroformate to produce a compound of formula (IV)

and(e) cyclisation of the compound of formula (IV) under basic conditionsto give the compound of formula (V);wherein ethyl acetate is employed as a solvent in step (d).38. A process for preparing a compound of formula (XII)

-   -   including the steps:        (f) contacting a compound of formula (IX) with methanesulfonyl        chloride and 2,6-lutidine followed by sodium thiomethoxide to        give a compound of formula (X)

(g) deprotection of the compound of formula (X) followed by conversionto a compound of formula (XI)

-   -   and        (h) conversion of the compound of formula (XI) to the compound        of formula (XII);        wherein acetone is employed as a solvent in step (f).        39. A process for preparing        (3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol        phosphate, including the steps:        (a) contacting a compound of formula (XII) with 9-deazaadenine        and formaldehyde in water/ethanol solvent to produce        (3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol

(b) contacting the(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olproduced in step (a) with:(i) a solution of phosphoric acid in water, to produce a solutioncontaining(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate;(ii) seed crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate; and optionally(iii) ethanol;to produce crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate;(c) isolating crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.

DEFINITIONS

The term “patient” includes human and non-human animals.

The terms “treatment”, “treating” and the like include the alleviationof one or more symptoms, or improvement of a state associated with thedisease or disorder, for example in the case of cancer, a reduction intumour size or suppression of tumour growth.

Synthesis of Compound (I)

(3R,4S)-1-((4-Amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,compound (I), and its phosphate salt,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, compound (Ia), are synthesised by the convergence of tworeaction pathways.

The first pathway is a five step process to afford the 9-deazaadenine(VII) as shown in Scheme 1.

Compound (III) is formed from an olefin addition-elimination reaction ofcompound (II) with aminoacetonitrile bisulfate in the presence oftriethylamine in methanol. The order of addition is carefully controlledto mange the associated exotherm (4.6° C. temperature rise over 5minutes addition on 10 g scale). Compound (III) is further reacted withmethyl chloroformate (MCF). Advantageously, the present process usesethyl acetate in this step, minimising the use of toxic solvents. It ispreferred that dry ethyl acetate is used. The formation of compound (IV)is complete in approximately 10 minutes.

The present inventors have found that variation of temperature andolefin concentration has a strong influence on yield, and that thecyclised product can be unstable. The present process employs a suitablyshort reaction time in order to minimise the degradation of the cyclisedproduct (V). The free pyrrole, compound (V), is readily precipitatedfrom a variety of solvents leading to a convenient and scale-friendlymethod for purification and improved yield and purity.

It is surprisingly found that precipitation of compound (V) fromethanol/water removes many of the impurities formed during cyclisationand any residual colour from the reaction. However two impurities remainand their removal at a later stage is required. Increasing the scale ofthe reaction gives consistent results with compound (V) isolated in 72%yield and 82.8% purity. Thus, advantageously, compound (V) is producedin solid form in high purity.

The synthesis of compound (VI) involves isolation of the product andsubsequent re-charging of the reaction. In this way, it is surprisinglypossible to obtain approximately full conversion. Saponification ofcompound (VI) followed by decarboxylation removes the ester group. Asthe reaction nears completion it is common to observe crystallisation ofthe product which results in high purity of approximately 99.74%,indicating that purification occurs on crystallisation which isadvantageous for scale-up procedures.

The second pathway is a four step process to afford the pyrrolidine(XII) as shown in Scheme 2.

Removal of the benzyl protecting group from (VIII) is achieved byhydrogenolysis using Pearlman's catalyst (10 wt % charge relative to(VIII)) under balloon pressure of hydrogen in ethanol. If hydrogenolysisstalls, a second charge of catalyst can be used to achieve conversion.The catalyst is removed via filtration and the resulting solutiontreated with di-t-butyl dicarbonate. Once gas evolution has stopped themixture is evaporated to give a quantitative yield of compound (IX)which is used without any further purification.

It has previously been found that mesylation of compound (IX) at the6-position can be difficult due to participation of the nitrogen in thereaction (Tet. Asymm., 9, 1998, 1051-1057). Only moderate protectinggroup selectivity is observed resulting in mixtures of the 3-mesyl,6-mesyl and bis-mesyl protected compounds. This can result in poor yieldof the desired product compound (X). However, the present inventors havefound that reaction of compound (IX) with methanesulfonyl chloride in anacetone/lutidine system followed by thiomethoxide displacement givescompound (X) in good yield and purity after chromatography.

Deprotection of compound. (X) is traditionally accomplished using anaqueous HCl/methanol mixture followed by evaporation to dryness. Thepresent process involves a scale-friendly approach using trifluoroaceticacid and food-grade strong base ion-exchange resins such as AmberliteFPA91 and FPA98 in isopropyl alcohol.

For complete basification, it is important to allow sufficient contacttime of the substrate with the resin. This is achieved through slurryingthe compound in an IPA solution with the resin for twenty minutes,followed by loading of the slurry on to a column containing more resinand eluting under gravity. Approximately 10 times the weight of resinrelative to compound (X) is required for complete deprotection. The useof ion-exchange resin provides a reliable method for generation of crude(XII) in free base form. Advantageously, a crystalline salt form isprovided for handling on scale-up. Crystallisation of the oxalate saltfrom ethanol gives a filterable crystalline slurry of the pyrrolidine asthe oxalate salt (XI) in 80% yield in high purity.

The final stage in the preparation of compound (Ia) is shown in Scheme3. Oxalate salt, compound (XI), is first converted to the free base(XII) using Amberlite FPA91 ion exchange resin in water to give (XII)before coupling with (VII) and formaldehyde in water/ethanol to givecompound (Ia). Following coupling, phosphoric acid is charged along withethanol as an antisolvent to crystallise compound (Ia) from solution. Awater/ethanol ratio of about 45:55 to about 15:85, e.g. about 40:60 isselected to facilitate controlled crystallisation of (Ia) via gradualaddition of ethanol as the antisolvent. Compound (Ia) can berecrystallised from water/ethanol or water/methanol.

A crystallisation screen of compound (I) with a number of counter-ionsindicates that the oxalate, sulfate, formate and phosphate salts arecrystalline. Microanalyses of the phosphate, formate and sulfate saltswith interpreted stoichiometries are given below (Table 1).

TABLE 1 Microanalysis of salt forms of compound (I) Formula Form C (%) H(%) N (%) S (%) P (%) compound B Calculated 36.52 5.89 16.38 — —(I)•H₂SO₄•2(H₂O) Found 36.63 6.04 16.29 — — compound D Calculated 35.815.62 16.06 — 9.23 (I)•1.30(H₃PO₄)•0.86(H₂O) Found 35.83 5.50 15.94 —9.77 compound E Calculated 35.36 5.52 15.86 — 10.22(I)•1.43(H₃PO₄)•0.44(H₂O) Found 35.35 5.52 15.87 — 10.00 compound FCalculated 35.36 5.52 15.86 — 10.22 (I)•1.43(H₃PO₄)•0.44(H₂O) Found35.34 5.52 15.86 — 10.10 compound G Calculated 49.54 6.24 20.63 9.45 —(I)•HCO₂H Found 49.42 6.42 20.75 9.56 —

X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC)and thermogravimetric analysis (TGA) indicate that compound (Ia),(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, exists as polymorphic forms. All forms show similarity in DSCanalysis.

TABLE 2 Polymorphs of Compound (Ia) Crystal Form Antisolvent E EtOH(64%) D EtOH (40%) F MeOH

Compound I(a),(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, exists as two polymorphic forms, D and E, isolated fromethanol, and one polymorphic form, F, isolated from methanol, as shownin Table 2 above.

Recrystallisation of crystal forms D and E can be utilised as a means ofincreasing purity by dissolution in water with warming to about 38° C.,addition of ethanol and subsequent cooling to 30° C. Seed crystals areadded followed by further cooling to 20° C. over 1 h. Ethanol is addedslowly and the slurry aged for 1 h. A second portion of ethanol is addedand the slurry aged for 1 h. A third portion of ethanol is added and theslurry aged for 1 h. The crystals are collected on filter paper andwashed with ethanol and dried under vacuum (FIG. 9). The level ofresidual ethanol (by ¹H NMR) is approximately 0.5 wt % and thiscorresponds to the ICH guidance for an oral active pharmaceuticalingredient.

Recrystallisation of crystal form F can also be utilised as a means ofincreasing purity by the same procedure described above, substitutingethanol with methanol.

Further Aspects

Salt forms of compound (I), e.g. compound (Ia),(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, may be administered to a patient by a variety of routes; itsroute of administration is not limited. Such administration routesinclude oral, parenteral, topical, rectal, nasal, buccal, by inhalationspray, or via an implanted reservoir.

The amount of compound to be administered will vary widely according tothe nature of the patient and the nature and extent of the disorder tobe treated. Typically the dosage for an adult human will be in the rangeless than 1 to 1000 milligrams, preferably 0.1 to 100 milligrams. Thecompounds can be administered using a variety of dosage regimes, forexample once daily or twice daily doses. Those skilled in the art willappreciate that the dosage regimes will vary according to the nature ofthe patient and the nature and extent of the disorder to be treated.

Salt forms of compound (I), e.g. compound (Ia), can be provided aspharmaceutical compositions. Salt forms of compound (I), e.g. compound(Ia), may be formulated into solid or liquid preparations such astablets, capsules, suppositories, powders, solutions, suspensions anddispersions. In some embodiments the salt forms of compound (I), e.g.compound (Ia), are formulated for oral administration as solid or liquidpreparations, for example tablets, capsules, powders, solutions,suspensions or dispersions. Such preparations are well known in the art.In tablet form, the salt forms of compound (I), e.g. compound (Ia), maybe tableted with conventional tablet bases such as glucose, lactose,sucrose, mannitol, and corn starch; together with a binder for example,corn starch or gelatin; a disintegration agent such as carboxymethylcellulose, poly vinyl pyrrolidinone, potato starch, alginic acid, andgelatin; and a lubricant such as magnesium stearate or talc. For oraladministration in the form of capsules, diluents such as lactose anddried cornstarch may be employed. Other components such as colourings,sweeteners or flavourings may be added.

When aqueous suspensions are required for oral use the salt forms ofcompound (I), e.g. compound (Ia), may be combined with carriers such aswater and ethanol, and emulsifying agents, suspending agents and/orsurfactants may be used. Colourings, sweeteners, flavourings or pHregulators may also be added.

Salt forms of compound (I), e.g. compound (Ia), may further beadministered by means of sustained release systems. For example, theymay be incorporated into a slowly dissolving tablet or capsule.

Liquid forms include carriers such as water and ethanol, with or withoutother agents such as pharmaceutically acceptable surfactants orsuspending agents.

The salt forms of compound (I), e.g. compound (Ia), may also beadministered by injection in a physiologically acceptable diluent suchas water or saline. The diluent may comprise one or more otheringredients such as ethanol, propylene glycol, an oil or apharmaceutically acceptable surfactant.

The salt forms of compound (I), e.g. compound (Ia), may be present asingredients in creams, for topical administration to skin or mucousmembranes. Preferably the creams include a pharmaceutically acceptablesolvent to assist passage through the skin or mucous membranes. Suitablecreams are well known to those skilled in the art.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows, for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate: FIG. 1( a) X-ray powder diffraction (measured using a Bruker D8Advance diffractometer); FIG. 1( b) DSC trace (measured using aMettler-Toledo DSC1 Star-e system), melting endotherm onset at 137.04°C. (scanning from 25° C. to 300° C.; scan rate 10° C./min).

FIG. 2 shows, for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate: FIG. 2( a) X-ray powder diffraction (measured using a Bruker D8Advance diffractometer); FIG. 2( b) DSC trace (measured using aMettler-Toledo DSC1 Star-e system), no obvious melting transition(scanning from 25° C. to 300° C.; scan rate 10° C./min).

FIG. 3 shows, for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, Form D, isolated from 60/40 water/ethanol: FIG. 3( a) X-raypowder diffraction (measured using a Phillips PW1700 diffractometer);FIG. 3( b) TGA, initial weight loss of 4.6% (scanning from ambienttemperature to 300° C.; scan rate 10° C./min); FIG. 3( c) DSC trace(measured using an Alphatec SDT Q600 instrument), melting endothermonset at 163.30° C. (scanning from 25° C. to 300° C.; scan rate 10°C./min); FIG. 3( d) TGA derivative.

FIG. 4 shows, for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, Form E, isolated from 3.6/6.4 water/ethanol: FIG. 4( a) X-raypowder diffraction (measured using a Phillips PW1700 diffractometer);FIG. 4( b) TGA, initial weight loss of 5.7% (scanning from ambienttemperature to 300° C.; scan rate 10° C./min); FIG. 4( c) DSC trace(measured using an Alphatec SDT Q600 instrument), melting endothermonset at 173.53° C. (scanning from 25° C. to 300° C.; scan rate 10°C./min); FIG. 4( d) TGA derivative.

FIG. 5 shows, for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, Form F, isolated from methanol: FIG. 5( a) X-ray powderdiffraction (measured using a Phillips PW1700 diffractometer); FIG. 5(b) TGA, initial weight loss of 3.9% (scanning from ambient temperatureto 275° C.; scan rate 10° C./min); FIG. 5( c) DSC trace (measured usingan Alphatec SDT Q600 instrument), melting endotherm onset at 177.06° C.(scanning from 25° C. to 300° C.; scan rate 10° C./min); FIG. 5( d) TGAderivative.

FIG. 6 shows, for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate, isolated from water/acetone: FIG. 6( a) X-ray powderdiffraction (measured using a Bruker D8 Advance diffractometer); FIG. 6(b) TGA, no initial weight loss (scanning from ambient temperature to275° C.; scan rate 10° C./min); FIG. 6( c) DSC trace (measured using anAlphatec SDT Q600 instrument), melting endotherm onset at 179.54° C.(scanning from 25° C. to 300° C.; scan rate 10° C./min); FIG. 6( d) TGAderivative.

FIG. 7 shows, for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol:FIG. 7( a) XRPD (measured using a Bruker D8 Advance diffractometer);FIG. 7( b) DSC trace (measured using a Mettler-Toledo DSC1 Star-esystem), melting endotherm onset is 184.82° C. (scanning from 25° C. to300° C.; scan rate 10° C./min).

FIG. 8 shows a study of the effect of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate on larger tumours (150 mm³).

FIGS. 9( a) and 9(b) show images of crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, Form E, at (a) 20 times magnification and (b) 50 timesmagnification.

ABBREVIATIONS

DBU 1,8-diazabicycloundec-7-eneDCM dichloromethaneDSC differential scanning calorimetryXRPD X-ray powder diffractionTLC thin layer chromatographyTFA trifluoroacetic acidTGA thermogravimetric analysisDMAP 4-dimethylaminopyridineMTBE methyl t-butyl etherIPA isopropyl alcoholHPLC high performance liquid chromatographyDSC differential scanning calorimetryGC gas chromatography

EXAMPLES General

X-ray powder diffraction patterns are obtained using parallel beam X-raypowder diffractometry using Co Kα radiation using either a Bruker D8Advance diffractometer (for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oland(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate, oxalate and formate) or a Philips PW1700 diffractometer (for(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate forms). The Bruker D8 Advance is equipped with 300 mmgoniometer radius, an incident beam goebel mirror and 0.23 degreeparallel plate diffracted beam collimator. The detector is a NaI(TI)scintillation counter. The Philips PW1700 series Bragg-Brentanodiffractometer is equipped with 173 mm goniometer radius, automaticdivergence and 1 degree fixed antiscatter slits, 0.2 mm receiving slitand graphite diffracted beam monochromator. The detector is a xenonfilled proportional counter.

Differential scanning calorimetry is performed on either aMettler-Toledo DSC1 Star-e system or an Alphatec SDT Q600 instrument,scanning from 25° C. to 300° C.; scan rate 10° C. per minute.

Thermogravimetric analysis is performed on an Alphatec SDT Q600instrument, scanning from ambient temperature to either 300° C. or 275°C.; scan rate 10° C. per minute.

Example 1 Synthesis of Compound (Ia)(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Compound (III) (E)-ethyl 2-cyano-3-(cyanomethylamino)acrylate

Aminoacetonitrile bisulfate (22.8 g, 0.148 mols) in methanol (0.5 L, ARgrade) is agitated for sufficient time so as to break up and dissolveany lumps of material present. Acrylate (25 g, 0.148 mols) is charged tothe mixture and the temperature cooled to 5-10° C. Triethylamine (45.3ml, 0.33 mols) is added gradually so as to maintain an internaltemperature of less than 20° C. The mixture is agitated for 2 hours andanalysed by TLC for consumption of starting material. The solvent isremoved in vacuo and the residue is dissolved in ethyl acetate (0.3 L)then washed with saturated aqueous sodium bicarbonate (0.2 L) and brine(0.08 L, 30%). The ethyl acetate solution is concentrated to give theproduct in quantitative yield before dissolution with an equal volume offresh ethyl acetate (AR grade) for use in the next step (characterisedas a 60:40 isomeric mixture, H′=minor isomer protons). δ_(H) (500 MHz,d⁶-DMSO) 1.21 (3H, t, J 7.1), 1.23 (3H′, t, J 7.2), 4.14 (2H, q, J 7.1),4.17 (2H′, q, J 7.2), 4.44 (2H′, s), 4.53 (2H, s), 7.86 (1H′, bd, J11.3), 8.16 (1H, s), 9.00 (1H, bs), 9.27 (1H′, bs); δ_(C) (125 MHz,d⁶-DMSO) 14.0, 14.3, 36.1, 36.8, 60.1, 71.9, 72.7, 115.7, 116.9, 116.9,118.2, 159.9, 160.1, 164.3, 165.7; m.p. 95° C.; HRMS calculated forC₈H₉N₃O₂Na m/z 202.0592. found 202.0590.

Compound (IV) (E)-ethyl2-cyano-3-((cyanomethyl)(methoxycarbonyl)amino)acrylate

Compound (III) (0.148 mols) in ethyl acetate is cooled to 5-10° C.Methyl chloroformate (12.6 ml, 0.163 mols) is added, followed by gradualaddition of triethylamine (22.7 ml, 0.163 mols) so as to maintain aninternal temperature of less than 25° C. After complete addition thereaction mixture is stirred for 10 minutes and then warmed to 20° C. Thereaction mixture is washed with deionised water (0.15 L), aqueoussaturated sodium bicarbonate (0.15 L) and brine (0.05 L, 30%). Thesolvent is removed in vacuo to give the product as orange oil inquantitative yield. δ_(H) (500 MHz, d⁶-DMSO) 1.27 (3H, t, J 7.1), 3.94(3H, s), 4.27 (2H, q, J 7.1), 5.07 (2H, s), 8.44 (1H, s); δ_(C) (125MHz, d⁶-DMSO) 14.0, 34.2, 56.0, 62.1, 83.6, 114.0, 115.3, 149.4, 151.9,162.6; HRMS calculated for C₁₀H₁₁N₃O₄Na m/z 260.0647. found 260.0652.

Compound (V) ethyl 4-amino-5-cyano-1H-pyrrole-3-carboxylate

Compound (IV) (35.1 g, 0.148 mols) is dissolved in dichloromethane (0.39L) and the temperature is adjusted to 27° C. DBU (12.5 ml, 0.083 mols)as a solution in dichloromethane (12.5 ml) is added to the solution ofcompound (IV) over approximately 1 minute with vigorous stirring. Onceaddition is complete, the mixture is agitated for 10 minutes and thejacket set to 20° C. Methanol (39 ml, AR grade) is added and the mixtureis agitated for 15 minutes, followed by addition of ammonium acetate(7.98 g, 0.104 mols) as a solution in methanol (60 ml). The solvent isremoved in vacuo and the residue slurried in absolute ethanol (70 ml).Water (280 ml) is gradually added to the slurry with stirring, andstirring continued for at least 2 hours. The mixture is then filtered,washed with water (80 ml) and dried under vacuum to give 19 g of solid(72%) of 80% purity as established by IPC. IPC is performed using aKinetix C18 2.6μ 100×3.0 mm column, at 40° C. with a flow rate of 0.3ml/min and a sample concentration of 0.5 mg/ml at a wavelength of 255nm. Solvent A is water+0.1% TFA and solvent B is acetonitrile+0.1% TFA;gradient conditions are 0-20 mins, A:B, 9:1; 20-22 mins, A:B, 1:1; 22-27mins, A:B, 9:1. δ_(H) (500 MHz, d⁶-DMSO) 1.26 (3H, t, J 7.1), 4.20 (2H,q, J 7.1), 5.65 (2H, s), 7.35 (1H, s), 11.8 (1H, bs); δ_(C) (125 MHz,d⁶-DMSO) 14.3, 59.1, 84.4, 102.3, 114.8, 127.4, 146.0, 164.0; m.p. 205°C.; HRMS calculated for C₈H₉N₃O₂Na m/z 202.0592. found 202.0591.

Compound (VI) ethyl 4-amino-5H-pyrrolo[3,2-d]pyrimidine-7-carboxylate

Compound (V) (19.1 g, 0.107 mol), formamidine acetate (16.7 g, 0.16mols), and formamide (0.2 L, AR grade) are charged to a vessel andheated at 90° C. for 20 hours. The mixture is cooled to below 50° C.,water (0.3 L) is added to the stirred suspension and the temperatureadjusted to 10-20° C. After 2 hours equilibration the mixture isfiltered and the solid is washed with water (50 ml) and briefly airdried. The dried solid is obtained in 16-18 g (90-100% yield whenadjusted for 80% purity of the starting material). The product is oflower solubility than the starting material and purity is determined byIPC analysis and calculation of the reduction of starting material IPCis performed using a Kinetix C18 2.6μ 100×3.0 mm column, at 40° C. witha flow rate of 0.25 ml/min and a sample concentration of 0.5 mg/ml at awavelength of 205 nm. Solvent A is water+0.1% TFA and solvent B isacetonitrile+0.1% TFA; gradient conditions are 0-25 mins, A:B, 9:1;25-26 mins, A:B, 4:6; 26-31 mins, A:B, 9:1. δ_(H) (500 MHz, d⁶-DMSO)1.29 (3H, t, J 7.1), 4.25 (2H, q, J 7.1), 6.85 (2H, bs), 8.16 (1H, s),8.20 (1H, s), 11.6 (1H, bs).

Compound (VII) 5H-pyrrolo[3,2-d]pyrimidin-4-amine

Wet compound (VI) (assumed dry weight 17.6 g, 0.085 mols) as asuspension in water (215 ml) is treated with potassium hydroxide (12.0g, 0.21 mols). The mixture is gently refluxed at 120° C. After 6 hoursthe mixture is analysed for completion by IPC. Heating and IPC analysisis continued until starting material is consumed. The mixture is cooledto 2-8° C. and stirred for 2 hours. The mixture is filtered, the solidcollected and washed with water (40 ml). The damp solid is dried undervacuum at 20-40° C. to give 9-10 g (80-90% purity as determined by IPC)of a beige solid. IPC is performed using an Atlantis T3 3μ 150×4.6 mmcolumn, at 20° C., with a flow rate of 1.0 ml/min, a sampleconcentration of 0.5 mg/ml at a wavelength of 273 nm. Solvent A iswater+0.1% TFA and solvent B is acetonitrile+0.1% TFA; gradientconditions are 0-15 mins, A:B, 10:0; 15-16 mins, A:B, 8:2; 16-21 mins,A:B, 10:0.

δ_(H)(500 MHz, d⁶-DMSO) 6.34 (1H, s), 6.66 (2H, bs), 7.50 (1H, s), 8.10(1H, s), 10.91 (1H, bs).

Compound (IX) (3R,4R)-tert-butyl3-hydroxy-4-(hydroxymethyl)pyrrolidine-1-carboxylate

Compound (VIII) (which can be prepared as described in WO 2005/118532)(1 g, 4.82 mmol) in ethanol (10 ml) is degassed and then treated withPearlman's catalyst (0.1 g). The mixture is stirred under low pressureof hydrogen and the reaction progress is monitored by TLC, more catalyst(0.1 g) is added if the reaction stalls. Once the starting N-benzylmaterial is consumed, the mixture is filtered through a pad of filteraid and di-t-butyl dicarbonate (1.26 g in total, 5.79 mmol) is added tothe filtrate, gas evolution and a mild exotherm are observed. Onceoff-gassing has subsided, DMAP (13 mg) is added resulting in furtheroff-gassing. Once gas evolution has stopped, the solvent is removed invacuo to give 1 g of colourless oil. δ_(H) (500 MHz, CD₃OD) 1.45 (9H,s), 2.23 (1H, m), 3.21 (2H, m), 3.45 (1H, m), 3.54 (3H, m), 4.13 (1H,m).

Compound (X) (3R,4S)-tert-butyl3-hydroxy-4-(methylthiomethyl)pyrrolidine-1-carboxylate

Compound (IX) (20.6 g, 0.093 mols) is isolated from an acetone solution(0.10 L) concentration in vacuo. The residue is redissolved in acetone(0.20 L) and treated with 2,6-lutidine (22.1 ml, 0.19 mols) followed bymethanesulfonyl chloride (8.0 ml, 0.10 mols). The solution is stirred at15-20° C. for two days and analysed for completion by IPC. The mixtureis filtered and the solids washed with a small volume of acetone. Thecombined filtrates are transferred to a reaction vessel and treated withsodium thiomethoxide (8.6 g, 0.12 mols). The mixture is heated at 50° C.for 2 hours and monitored by IPC. Once complete, the reaction isconcentrated and the residue partitioned between MTBE (0.2 L) andaqueous sodium hydroxide (1 M, 0.2 L). The aqueous phase is extractedonce more with MTBE (0.2 L) and the combined MTBE phases are washedsuccessively with hydrochloric acid (1 M, 0.2 L) and water (0.2 L). MTBEis removed by distillation and toluene azeotrope (0.2 L). The residue istaken up in dichloromethane/ethyl acetate (90:10, 0.11 L) and applied toa Biotage 75 S cartridge (200 g silica). The column is eluted with 90:10dichloromethane/ethyl acetate then 66/33 dichloromethane/ethyl acetate.The fractions are assayed by TLC and the product-containing fractionsare concentrated to give 14.8 g (63%) of compound (X) as a pale yellowto colourless oil. IPC analysis is performed at 205 nm using a KinetixC18 2.6μ 100×3.0 mm column, at 40° C. with a flow rate of 0.25 ml/minand a sample concentration of 0.5 mg/ml. Solvent A is water, solvent Bis acetonitrile; gradient conditions are 0-25 mins, A:B, 9:1; 25-26mins, A:B, 4:6; 26-31 mins, A:B, 9:1. δ_(H) (500 MHz, CD₃OD) 1.46 (9H,s), 2.11 (3H, s), 2.28 (1H, m), 2.49 (1H, m), 2.63 (1H, dd, J 13.1,6.0), 3.20 (2H, m), 3.56 (1H, m), 3.60 (1H, dd, J 11.1, 7.2), 4.10 (1H,m).

Compound (XI) (3R,4S)-4-(methylthiomethyl)pyrrolidin-3-ol oxalate salt

Compound (X) (7.24 g, 29.3 mmol) is dissolved in toluene (50 ml) andconcentrated. The residue is redissolved in toluene (50 ml, AR grade)and the solution cooled to 0° C. TFA (25 ml) is added with stirring,resulting in steady gas evolution. After 20 minutes, the temperature israised to 20° C., and the mixture may become biphasic. Once off-gassinghas stopped after approximately 40 minutes, the solvents are removed invacuo and any residual solvent is azeoptroped with IPA (40 ml). Theresidue is redissolved in IPA (75 ml, AR grade) and slurried withAmberlite FPA91 basic resin (60 g wet weight) for 30 minutes. The pH ofsolution is verified as ≧7. The slurry is applied to a column of FPA91resin (20 g) and eluted with IPA (350 ml) under gravity. The IPA isevaporated to give the 5 g of free base as a brown oil. The oil isdissolved in ethanol (50 ml) and added slowly, with stirring, to asolution of oxalic acid (4.06 g, 32.1 mmol) in absolute ethanol (50 ml).After complete addition, the crystal slurry is aged for at least 2 hoursand the crystals collected by filtration. The crystals are washed withethanol (20 ml) and dried to give a white to off-white solid, 5.5 g(79%). δ_(H) (500 MHz, d⁶-DMSO) 2.07 (3H, s), 2.32 (1H, m), 2.41 (1H,dd, J 13.2, 9.0), 2.60 (1H, dd, J 13.2, 6.4), 3.01 (2H, m), 3.31 (1H,dd, J 12.2, 5.1), 3.40 (1H, dd, J 11.8, 7.3), 4.13 (1H, m).

Compound (XII) (3R,4S)-4-(methylthiomethyl)pyrrolidin-3-ol

Compound (XI) (4.0 g, 16.9 mmol) in water (80 ml) is slurried withAmberlite FPA91 resin (15 g) for 30 minutes. The slurry is applied to acolumn of FPA91 resin (15 g) and eluted with water (200 ml) undergravity, as required to bring off the product. Removal of water at 40°C. gives 2.68 g of orange oil, which is solidifies on storage at −20° C.GC is performed using an Rtx-5 amine capillary column 1μ, 30 m×0.32 mm,with a flow rate of 2.6 ml/min, at 100° C. then a gradient of at 8°C./min for 25 mins. δ_(H) (500 MHz, CD₃OD) 2.11 (3H, s), 2.19 (1H, m),2.43 (1H, dd, J 13.0, 8.7), 2.64 (2H, m), 2.78 (1H, dd, J 12.1, 3.5),3.01 (1H, dd, J 12.1, 5.5), 3.23 (1H, dd, J 11.6, 7.6), 4.05 (1H, m).

Compound (Ia)(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate

Compound (XII) (15.6 g, 106 mmol) as a solution in water/ethanol (4:1,375 ml) is treated with compound (VII) (12.8 g, 95.4 mmol) andformaldehyde solution (8.66 ml, 35%). The mixture is stirred atapproximately 20° C. for 24 hours and monitored by IPC until thestarting material is consumed. Phosphoric acid (9.35 ml, 138 mmol) isadded with stirring. A precipitate begins to form. After 30 mins ethanol(200 ml) is slowly added to the vessel and the mixture aged for 1 h,further ethanol (300 ml) is added and the mixture aged for 1 h. Thenmore ethanol (300 ml) is added and the mixture is allowed to standovernight. The crystals are collected by filtration and are washed withethanol/water (4/6, 200 ml), followed by ethanol (2×200 ml), and driedunder vacuum to give 36.4 g (97%) of product as a white to off-whitesolid. IPC is performed using a Waters T3 3μ 150×4.6 mm, at 35° C. witha flow rate of 0.8 ml/min and a sample concentration of 0.5 mg/ml at awavelength of 273 nm. Solvent A is water+0.1% TFA and solvent B isacetonitrile+0.1% TFA; gradient conditions are 0-25 mins, A:B, 9.5:0.5;20-21 mins, A:B, 7.8:2.2; 21-26 mins, A:B, 9.5:0.5. This material isdissolved in hot water (150 ml) and methanol (500 ml) is added slowlykeeping the solution at boiling point and then allowed to cool. Theproduct is collected by filtration and washed with methanol to give 33.0g (88%). Anal. Calc. for C₁₃H₁₉N₅OS.1.4H₃PO₄.H₂O; C, 34.8; H, 5.7; N,15.6; P, 9.7. Found: C, 34.5; H, 5.6; N, 15.5; P, 9.9. δ¹³C NMR (D₂O)150.1, 146.6, 140.4, 133.7, 113.0, 102.5, 72.8, 58.5, 55.5, 47.6, 44.9,34.0, 14.4.

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form D

Compound (XII) (2.48 g, 16.9 mmol) is stirred in water/ethanol (4:1, 80ml) and treated with 9-deazaadenine (2.06 g, 15.3 mmol) and formaldehydesolution (1.11 ml, 38%). The mixture is stirred at ambient temperaturefor 2 days. A solution of phosphoric acid (2.25 g, 23.0 mmol) in water(10 ml) is prepared. A portion of this solution (6 ml) is slowly addedto the mixture with stirring. Seed crystals (76 mg) are added and themixture aged for 1 h. The remaining acid solution is slowly charged withstirring; the mixture is aged for 1 h. Ethanol (35 ml) is slowly chargedto the vessel and the mixture aged for 1 h. Further ethanol (60 ml) isslowly charged to the vessel and the mixture aged for 1 h. The mixtureis filtered and the crystals washed with ethanol/water (40/60, 25 ml),followed by ethanol (2×25 ml). The crystals are dried under vacuum togive the product as a white to off-white solid, 4.7 g (70%).

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form E

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate (1 g) is stirred in water (18 ml) and heated to 40° C. todissolve. Ethanol (2 ml) is added along with(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate seed crystals (25 mg). The resulting mixture is cooled toapproximately 15° C. After 1 h ethanol (5 ml) is added to the stirredsolution. After a further 1 h ethanol (10 ml) is added to the stirredsolution. After a further 1 h ethanol (15 ml) is added and the slurrystirred overnight. The mixture is filtered on filter paper and thecrystals washed with ethanol (approximately 10 ml). The crystals aredried under vacuum giving 775 mg white solid.

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate Form F

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate (36.3 g) is dissolved in boiling water (150 mL) and methanol(500 ml) is added slowly while maintaining reflux of the solution. Theresulting mixture is cooled to 15° C. and agitated for 18 hours. Theresulting crystals are filtered, washed with methanol (approx. 50 ml)and dried to give a white solid, 33.0 g (91%).

Example 2 Sulfate, Oxalate and Formate Salts of Compound (I)(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol

Compound (XII) (457 mg, 3.10 mmol) is stirred in water/ethanol (4:1,22.5 ml) and treated with 9-deazaadenine (378 mg, 2.82 mmol) andformaldehyde solution (0.21 ml, 38%). The mixture is stirred at ambienttemperature for 3 days. A solution of sulfuric acid (2.8 ml, 1M) isadded. Ethanol (5 ml) is added. The mixture is cooled to 0° C. andstirred for 15 minutes. The resulting slurry is filtered and thecrystals dried to give 548 mg tan solid. A portion of this solid (300mg) is stirred in water (approximately 10 ml) with Amberlite FPA91-OHresin (approximately 2 g) for 30 minutes. The resin is filtered and thesolution evaporated to give 143 mg white solid((3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olwhich is used in the next steps).

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olSulfate

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol(50 mg, 0.17 mmol) is dissolved in water (1.0 ml) and treated withsulfuric acid (0.17 ml, 1M, 1.0 eq). IPA (0.4 ml) is added and theresulting solution stored at 4° C. resulting in formation of an oilphase. The mixture is warmed to give a solution, treated with ethanol(approximately 0.2 ml) and stored at 4° C. overnight resulting inprecipitation of solids from solution. The solid is filtered on filterpaper and dried under vacuum.

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olOxalate

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol(50 mg, 0.17 mmol) is dissolved in water (1.0 ml) and treated withoxalic acid dihydrate (22 mg, 0.17 mmol). IPA (0.4 ml) is added and theresulting solution stored at 4° C. resulting in formation of solids. Thesolid is filtered on filter paper and dried under vacuum.

3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olFormate

(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol(0.983 g, 3.35 mmol) is suspended in water (3 ml) and formic acid (0.25ml, 6.70 mmol) is added. The mixture is warmed to approximately 40° C.to dissolve. Ethanol (approx. 10 ml) is added. The mixture is evaporatedto dryness and re-suspended in water (2 ml) and acetone added (approx.30 ml) resulting in formation of pale yellow crystals (0.71 g). Aportion of this material (0.65 g) is dissolved in water (2.5 ml) anddiluted with acetone (30 ml). The resulting crystals are filtered anddried to give 0.55 g (52% yield from the free base) cream colouredsolid.

Example 3 X-Ray Powder Diffraction Data for Compounds of the Invention

2-theta d value Intensity degrees Angstrom Count(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol phosphate Form D 5.38 19.075 283 7.1014.448 103 8.93 11.487 137 10.87 9.443 104 13.06 7.865 84.2 14.31 7.18185.8 14.57 7.053 58.7 15.32 6.709 70.4 15.81 6.504 152 16.50 6.232 88.717.59 5.849 256 17.92 5.742 357 19.07 5.4 72.6 19.97 5.159 175 20.175.108 105 20.77 4.963 112 21.53 4.789 397 21.78 4.734 355 22.22 4.643144 22.76 4.534 267 23.12 4.463 161 24.84 4.159 145 25.75 4.014 65326.00 3.977 722 26.31 3.931 392 27.06 3.823 283 27.79 3.725 265 28.143.679 211 28.57 3.625 202 28.95 3.579 296 29.35 3.531 302 29.97 3.459299 30.50 3.401 217 30.91 3.357 305 31.35 3.311 305 32.64 3.183 21732.09 3.236 351 34.17 3.045 204 33.33 3.119 150(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol phosphate Form E 5.26 19.479 667 7.0114.623 100 8.69 11.801 133 8.90 11.522 87.2 10.58 9.704 283 12.56 8.17767 15.95 6.446 93 16.76 6.136 117 17.26 5.962 439 17.57 5.857 367 17.845.77 193 19.36 5.319 73 20.14 5.115 102 20.86 4.942 146 21.27 4.846 40421.60 4.773 408 22.09 4.669 126 22.52 4.58 241 22.75 4.536 322 23.034.481 146 24.14 4.278 82 25.64 4.031 714 25.95 3.984 606 26.16 3.952 51626.63 3.884 247 26.88 3.849 348 27.72 3.734 175 28.86 3.589 380 29.353.531 220 29.99 3.457 541 30.22 3.431 383 30.75 3.374 431 31.11 3.336242 31.57 3.288 294 32.38 3.208 173 33.04 3.146 242 33.38 3.115 18033.92 3.066 224(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol phosphate Form F 2-theta d valueIntensity degrees Angstrom % 5.25 19.534 71 7.00 14.654 21.5 8.73 11.75832.4 8.92 11.500 14.2 10.67 9.620 29.4 12.69 8.091 10.9 14.18 7.245 8.815.14 6.790 5.4 15.82 6.500 12.5 16.03 6.413 12 16.68 6.167 7.5 17.525.873 50.7 17.75 5.797 53.7 19.21 5.360 2.6 20.13 5.118 14.2 20.77 4.96212 21.36 4.827 46.9 21.72 4.748 36.9 22.09 4.669 8.9 22.79 4.527 40.323.60 4.374 5.3 24.35 4.241 5.1 24.80 4.165 6.2 25.70 4.022 100 26.103.962 74.2 26.80 3.859 22.5 27.00 3.832 18.2 27.81 3.722 11.3 28.553.627 42.5 29.01 3.571 12.7 29.56 3.506 27.5 29.88 3.469 17.1 30.523.398 45.1 31.42 3.303 21.9 32.12 3.233 18.5 32.42 3.204 31.4 32.953.154 15.2 33.68 3.088 4.8 34.08 3.052 9.9 35.08 2.968 5.6 35.84 2.9077.9 36.58 2.850 3.3 37.32 2.795 5.1 39.18 2.668 2.7 40.37 2.592 4 40.792.567 3.1 41.84 2.505 3.5 42.56 2.464 3 43.62 2.408 2.6 44.51 2.362 2.146.14 2.283 2.9 46.52 2.265 3.3 47.00 2.243 1.9 48.23 2.189 1.8 49.022.156 2.3 49.54 2.135 2.3(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol oxalate 2-theta d value Intensitydegrees Angstrom Count 6.22 16.498 364 12.35 8.318 104 13.54 7.588 15214.94 6.881 94 15.72 6.542 81.6 18.22 5.648 148 19.11 5.388 100 20.475.034 134 21.94 4.7 134 22.53 4.578 103 24.22 4.263 114 29.44 3.52 14930.07 3.448 130 31.11 3.336 115 32.06 3.239 145 32.71 3.177 115 33.903.068 86.1(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol formate 2-theta d value Intensitydegrees Angstrom % 8.11 12.650 100.0 10.34 9.927 1.7 13.66 7.522 2.316.30 6.311 54.6 17.54 5.868 6.5 17.94 5.735 5.0 18.83 5.469 0.8 20.684.983 34.0 21.32 4.835 5.0 21.71 4.749 1.2 23.17 4.454 2.9 24.63 4.1949.7 24.85 4.157 33.3 25.70 4.022 19.2 26.03 3.972 8.9 27.13 3.814 1.827.57 3.754 6.1 28.00 3.698 14.4 28.51 3.632 7.7 28.77 3.600 6.6 30.323.420 6.2 31.05 3.342 3.3 31.24 3.322 4.0 32.23 3.223 14.0 33.02 3.14710.1 33.45 3.108 1.7 34.24 3.039 5.1 34.52 3.014 3.3 35.57 2.929 1.435.99 2.896 1.9 36.65 2.845 4.7 36.92 2.825 1.2 38.15 2.737 0.9 38.902.686 2.6 39.94 2.619 3.7 40.47 2.586 0.6 41.45 2.528 3.6 42.17 2.4863.9 42.75 2.454 0.9 44.36 2.369 1.0 45.14 2.330 1.4 46.27 2.277 4.246.50 2.266 2.8 47.36 2.227 2.5 48.48 2.178 1.3 49.20 2.149 0.4 50.122.112 2.5 (3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol sulfate 2-theta d value Intensitydegrees Angstrom Count 5.75 17.828 233 10.33 9.936 111 13.14 7.818 11415.41 6.672 93.3 15.90 6.469 151 17.61 5.844 121 18.32 5.619 103 19.145.38 79.4 20.27 5.082 79.4 20.87 4.939 87.7 21.43 4.811 104 22.26 4.63382.8 24.30 4.25 131 24.64 4.192 87.3 26.15 3.954 93.3 26.76 3.866 10327.67 3.741 94.9 29.37 3.529 69.8 30.28 3.425 115 30.97 3.35 136 31.523.293 120 32.27 3.219 103 33.24 3.127 84.2

Example 4 Activity of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate against head and neck cancers, lung cancer, breast cancer,colon cancer, cervical cancer or prostate cancer

Female Ncr-Nu mice (6-8 weeks old) are obtained from NCI, NIH. Animalexperiments are conducted in accordance with approved protocolguidelines of the Animal Committee of the Albert Einstein College ofMedicine. Orthotopic mammary fat pad injections are performed at twoopposite inguinal fat pad of each mouse by re-suspending 2.5×10⁶MDA-MB-468 viable cells in 75 ml of PBS and mixing with 25 ml of rattail collagen, type I (BD) per site. At day 36, mice with establishedtumours (˜150 mm³) are randomly assigned to treatment or control groupsof five animals each followed by treatment with(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate at 30.5 mg/kg body weight in drinking water or by dailyintraperitoneal (i.p.) injections of 24 mg/kg body weight with andwithout 13 mg/kg methylthioadenosine. Tumour volume (V) is determined asfollows: V=(4/3)×(22/7)×1/8 (length×width×height). Differences betweentreatment cohorts are determined using the Student's t test. Mice areweighed every 4-5 days, monitored for hair loss, loss of appetite,vomiting, and diarrhea. Untreated control tumours grow from 150 to 400mm³ over a period of 35 days. Doses of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate from 24 to 30.5 mg/kg are equally effective at stopping cancergrowth. At day 71, animals being treated are released from therapy tosee if regrowth equals untreated tumour growth. Conversely, animals withthe large control tumours are treated with 30 mg/kg i.p.(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate. During treatment,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate completely suppresses tumour growth in the 150 mm³ tumours.Upon drug release, tumour size increases slowly relative to untreatedtumour growth. The large tumours undergo rapid decrease in size as aconsequence of tumour lysis. The bulk of the tumours resolve over atwo-week treatment period.

Although the invention has been described in connection with specificpreferred embodiments, it should be understood that the invention asclaimed should not be unduly limited to such specific embodiments.

It is appreciated that further modifications may be made to theinvention as described herein without departing from the spirit andscope of the invention.

1. A salt form of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol,selected from the group consisting of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate,(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate and(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-ol sulfate.
 2. A salt form of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olas claimed in claim 1, which is crystalline.
 3. A salt form as claimedin claim 1 which is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, a compound of formula (Ia):


4. A salt form as claimed in claim 1 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form D characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.38, 7.10, 8.93, 10.87, 13.06,14.31, 15.81, 17.59, 17.92, 19.97, 21.53, 22.76, 26.00, 27.06, 27.79,28.95 and 29.97 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 19.1, 14.4, 11.49,9.44, 7.87, 7.18, 6.50, 5.85, 5.74, 5.16, 4.79, 4.53, 3.977, 3.823,3.725, 3.579 and 3.459 Å.
 5. A salt form as claimed in claim 4 which isfurther characterised by one or more additional X-ray power diffractionpeaks at the following 2 theta angles: about 14.57, 15.32, 16.50, 19.07,20.17, 20.77, 21.78, 22.22, 23.12, 24.84, 25.75, 26.31, 28.14, 28.57,29.35, 30.50, 30.91, 31.35, 32.64, 32.09, 34.17, 33.33 degrees 2theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 7.05, 6.71, 6.23, 5.40, 5.11, 4.96, 4.73,4.64, 4.46, 4.159, 4.014, 3.931, 3.679, 3.625, 3.531, 3.401, 3.357,3.311, 3.183, 3.236, 3.045, 3.119 Å.
 6. A salt form as claimed in claim1 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form E characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.26, 7.01, 8.69, 10.58, 15.95,17.26, 17.57, 21.27, 21.60, 22.75, 25.64, 26.88, 28.86, 29.99 and 30.75degrees 2 theta±0.05 degrees 2 theta, which correspond, respectively, tothe following d-spacings: about 19.5, 14.6, 11.81, 9.70, 6.45, 5.96,5.86, 4.85, 4.77, 4.54, 4.031, 3.849, 3.589, 3.457 and 3.374 Å.
 7. Asalt form as claimed in claim 6 which is further characterised by one ormore additional X-ray power diffraction peaks at the following 2 thetaangles: about 8.91, 12.56, 16.76, 17.84, 19.36, 20.14, 20.86, 22.09,22.53, 23.03, 24.14, 25.95, 26.16, 26.63, 27.72, 29.35, 30.22, 31.11,31.57, 32.38, 33.04, 33.38, 33.93 degrees 2 theta±0.05 degrees 2 theta,which correspond, respectively, to the following d-spacings: about11.52, 8.18, 6.14, 5.77, 5.32, 5.12, 4.94, 4.67, 4.58, 4.48, 4.278,3.984, 3.952, 3.884, 3.734, 3.531, 3.431, 3.336, 3.288, 3.208, 3.146,3.115, 3.066 Å.
 8. A salt form as claimed in claim 1 which iscrystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate of Form F characterised by X-ray power diffraction peaks atthe following 2 theta angles: about 5.25, 7.00, 8.73, 10.67, 15.82,16.04, 17.52, 17.75, 20.13, 20.77, 21.36, 21.72, 22.79, 25.70, 26.10,28.55, 29.56, 30.52, 31.43 and 32.42 degrees 2 theta±0.05 degrees 2theta, which correspond, respectively, to the following d-spacings:about 19.5, 14.7, 11.76, 9.62, 6.50, 6.41, 5.87, 5.80, 5.12, 4.97, 4.83,4.75, 4.53, 4.022, 3.962, 3.627, 3.506, 3.398, 3.303 and 3.204 Å.
 9. Asalt form as claimed in claim 8 which is further characterised by one ormore additional X-ray power diffraction peaks at the following 2 thetaangles: about 8.92, 12.69, 14.19, 15.14, 16.68, 19.21, 22.09, 23.60,24.35, 24.80, 26.81, 27.00, 27.81, 29.01, 29.88, 32.12, 32.95, 33.68,34.08, 35.08, 35.84, 36.58, 37.32, 39.18, 40.37, 40.79, 41.84, 42.56,43.62, 44.51, 46.14, 46.52, 47.00, 48.24, 49.02, 49.54 degrees 2theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 11.50, 8.09, 7.25, 6.79, 6.17, 5.36, 4.67,4.374, 4.241, 4.165, 3.859, 3.832, 3.722, 3.571, 3.469, 3.233, 3.154,3.088, 3.052, 2.968, 2.907, 2.850, 2.795, 2.668, 2.592, 2.567, 2.505,2.464, 2.408, 2.362, 2.283, 2.265, 2.243, 2.189, 2.156, 2.135 Å.
 10. Asalt form as claimed in claim 1 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-oloxalate characterised by X-ray power diffraction peaks at the following2 theta angles: about 6.22, 12.35, 13.54, 18.23, 20.47, 21.94, 24.22 and29.44 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 16.5, 8.32, 7.59, 5.65,5.03, 4.70, 4.263 and 3.520 Å.
 11. A salt form as claimed in claim 10which is further characterised by one or more additional X-ray powerdiffraction peaks at the following 2 theta angles: about 14.94, 15.72,19.11, 22.54, 30.07, 31.11, 32.06, 32.71, 33.90 degrees 2 theta±0.05degrees 2 theta, which correspond, respectively, to the followingd-spacings: about 6.88, 6.54, 5.39, 4.58, 3.448, 3.336, 3.239, 3.177,3.068 Å.
 12. A salt form as claimed in claim 1 which is crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olformate characterised by X-ray power diffraction peaks at the following2 theta angles: about 8.11, 16.30, 20.68, 24.85, 25.70, 26.03, 28.00,32.23 and 33.02 degrees 2 theta±0.05 degrees 2 theta, which correspond,respectively, to the following d-spacings: about 12.65, 6.31, 4.98,4.157, 4.022, 3.972, 3.698, 3.223 and 3.147 Å.
 13. A salt form asclaimed in claim 12 which is further characterised by one or moreadditional X-ray power diffraction peaks at the following 2 thetaangles: about 10.34, 13.66, 17.54, 17.95, 18.83, 21.32, 21.71, 23.17,24.63, 27.13, 27.57, 28.51, 28.77, 30.33, 31.05, 31.24, 33.45, 34.24,34.52, 35.57, 35.99, 36.66, 36.93, 38.15, 38.91, 39.94, 40.47, 41.45,42.17, 42.75, 44.36, 45.15, 46.27, 46.50, 47.36, 48.49, 49.20, 50.12degrees 2 theta±0.05 degrees 2 theta, which correspond, respectively, tothe following d-spacings: about 9.93, 7.52, 5.87, 5.74, 5.47, 4.84,4.75, 4.45, 4.194, 3.814, 3.754, 3.632, 3.600, 3.420, 3.342, 3.322,3.108, 3.039, 3.014, 2.929, 2.896, 2.845, 2.825, 2.737, 2.686, 2.619,2.586, 2.528, 2.486, 2.454, 2.369, 2.330, 2.277, 2.266, 2.227, 2.178,2.149, 2.112 Å.
 14. A salt form as claimed in claim 1 which iscrystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olsulfate characterised by X-ray power diffraction peaks at the following2 theta angles: about 5.75, 10.33, 13.14, 15.41, 15.90, 17.61, 18.32,21.43, 24.30, 26.15, 26.76, 27.67, 30.28, 30.97, 31.52 and 32.27 degrees2 theta±0.05 degrees 2 theta, which correspond, respectively, to thefollowing d-spacings: about 17.8, 9.94, 7.82, 6.67, 6.47, 5.84, 5.62,4.81, 4.25, 3.954, 3.866, 3.741, 3.425, 3.35, 3.293 and 3.219 Å. 15-18.(canceled)
 19. A pharmaceutical composition comprising a salt form asclaimed in claim 1 and at least one pharmaceutically acceptableexcipient.
 20. A pharmaceutical composition as claimed in claim 19,wherein the salt form is(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.
 21. A method of treating a disease or disorder in which it isdesirable to inhibit MTAP, comprising administering an effective amountof a salt form as claimed in claim 1 to a patient in need thereof.
 22. Aprocess for the preparation of crystalline(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate, including the steps: (a) preparing a solution of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate in water; (b) adding an alcohol, methyl ethyl ketone,tetrahydrofuran or acetone to the solution, to form crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate; and (c) isolating the crystals of(3R,4S)-1-((4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)methyl)-4-(methylthiomethyl)pyrrolidin-3-olphosphate.
 23. A process for preparing a compound of formula (V)

including the steps: (d) reacting a compound of formula (III) withmethyl chloroformate to produce a compound of formula (IV)

and (e) cyclisation of the compound of formula (IV) under basicconditions to give the compound of formula (V); wherein ethyl acetate isemployed as a solvent in step (d).
 24. A process for preparing acompound of formula (XII)

including the steps: (f) contacting a compound of formula (IX) withmethanesulfonyl chloride and 2,6-lutidine followed by sodiumthiomethoxide to give a compound of formula (X)

(g) deprotection of the compound of formula (X) followed by conversionto a compound of formula (XI)

and (h) conversion of the compound of formula (XI) to the compound offormula (XII); wherein acetone is employed as a solvent in step (f).